DE602007000011T2 - An ink jet recording medium and manufacturing method therefor - Google Patents

Abstract

An inkjet-recording medium comprising a support and an ink-receiving layer formed thereon containing inorganic fine particles, a water-soluble aluminum compound, a zirconium compound, a cationic modified self-emulsifying polymer, a polyvinyl alcohol having a saponification value of 92 to 98 mol %, and a crosslinking agent, and a method of producing the same.

Description

BACKGROUND OF THE INVENTION

1. Field of the invention

The The present invention relates to an ink jet recording medium, i. H. a recording medium, that for the ink jet recording method can be suitably used can as well as a method for producing the same.

2. Description of the Related Art

in the In the wake of the rapid progress of the communications industry in the In recent years, there are various information processing systems been developed. Likewise, different recording methods and devices developed for this information processing Systems are suitably usable, and they are in use. Among these recording methods has, for example the ink jet recording method is widely used found, not only in office use, for .... As well the so-called private use, since the inkjet process the pressure allowed on different recording materials and the hardware (Equipment) for relative cheap, more compact and quieter work.

Furthermore is at the youngest Trend of the inkjet printer towards higher resolution and through the advancement of hardware (devices) a variety of media for the Inkjet recording has been developed. Recently, there are some Inkjet printer available, the pressure of so-called photographic quality images allow.

To general requirements regarding the properties of such an ink jet recording medium belong (1) high drying speed (high ink absorption speed), (2) cheaper and uniform ink dot diameter (without ink bleeding), (3) cheap graininess (4) high dot-circle shape; (5) high color density, (6) high color saturation (no dullness), (7) excellent light fastness, gas resistance and water resistance the printed image parts, (8) higher whiteness of the recording surface, (9) favorable storage stability of the recording medium (no yellowing and fading of the image while long - term storage), (10) deformation resistance and favorable dimensional stability (suppression of Curling or of the wave); (11) favorable transmission characteristics for the machine and similar. About that addition are for Applications as photographic glossy papers for printing of so-called photographic-like quality images be used, gloss, surface smoothness, similar Texture as with papers of silver halide photography and the like demanded, in addition to the above properties.

For ink jet recording media satisfying the above requirements, for example, there is known a medium in which an ink receiving layer is formed on a support by coating with a solution containing inorganic fine particles such as silica from a vapor phase process, a mordant such as a cationic polymer , a water-soluble resin such as polyvinyl alcohol (PVA) and a hardener for the water-soluble salt (eg, boric acid) ( JP-A-2000-211235 ), the medium carrying the ink-receiving layer is prepared by applying the solution containing the water-soluble resin hardener (boric acid, etc.), and thereby curing the layer coated on the support by coating with a solution of inorganic fine particles such as a vapor-phase silica, a metal compound such as a water-soluble metal salt, and a water-soluble resin such as PVA before the coated layer is completely dried ( JP-A-2001-334742 ).

Also, there is known a method for producing an ink jet recording medium in which an ink receiving layer of a crosslinked and cured coated layer is formed on a support, comprising forming the coated layer on the support by applying a first liquid, the inorganic fine particles containing a water-soluble resin and a crosslinking agent, and crosslinking and curing the coated layer by applying a second liquid containing a zirconium compound and a weak acid ammonium salt to the coated layer, namely (1) simultaneously with the application of the first liquid or (2) before the applied layer, formed by applying the first liquid, shows a falling rate of drying during the drying of the applied layer ( JP-A-2005-14593 ). It is possible with the method to form an ink-receiving layer that is durable enough to prevent problems such as breakage excellent in ink absorption capacity and water resistance, and resistant to yellowing, browning and beading.

Summary of the invention

The The present invention has been made in view of the above conditions develops and provides an ink jet recording medium and a method ready for production.

• (1) Ein Tintenstrahl-Aufzeichnungsmedium, umfassend einen Träger und eine darauf gebildete Tintenaufnahmeschicht, die anorganische feine Teilchen, eine wasserlösliche Aluminiumverbindung, eine Zirkoniumverbindung, ein kationisch modifiziertes selbstemulgierendes Polymeres, einen Polyvinylalkohol mit einem Verseifungswert von 92 bis 98 Mol-% und ein Vernetzungsmittel enthält.
• (2) Ein Verfahren zum Herstellen eines Tintenstrahl-Aufzeichnungsmediums, umfassend die Herstellung einer Dispersion durch Kollidierenlassen anorganischer feiner Teilchen und einer Zirkoniumverbindung oder durch Führen anorganischer feiner Teilchen und einer Zirkoniumverbindung durch eine Öffnung unter Verwendung einer Hochdruckdispergiervorrichtung; Herstellung einer Tintenaufnahmeschicht-bildenden Lösung durch Zusetzen eines kationisch modifizierten selbstemulgierenden Polymeren, eines Polyvinylalkohols mit einem Verseifungswert von 92 bis 98 Mol und eines Vernetzungsmittels zu der Dispersion; und Bilden einer beschichteten Schicht durch Aufbringen einer Beschichtungslösung, die durch In-line-Einmischen einer wasserlöslichen Aluminiumverbindung in die Tintenaufnahmeschicht-bildende Lösung hergestellt wird, auf einen Träger.
• (3) Ein Verfahren zur Herstellung eines Tintenstrahl-Aufzeichnungsmediums, umfassend die Herstellung einer Dispersion durch Kollidierenlassen anorganischer feiner Teilchen, einer Zirkoniumverbindung und eines Vernetzungsmittels oder durch Führen anorganischer feiner Teilchen, einer Zirkoniumverbindung eines Vernetzungsmittels durch eine Öffnung unter Verwendung einer Hochdruckdispergiervorrichtung; Herstellung einer Tintenaufnahmeschicht-bildenden Lösung durch Zusetzen eines kationisch modifizierten selbstemulgierenden Polymeren und eines Polyvinylalkohols mit einem Verseifungswert von 92 bis 98 Mol-% zu der Dispersion; und Bilden einer beschichteten Schicht durch Aufbringen einer Beschichtungslösung, die durch In-line-Einmischen einer wasserlöslichen Aluminiumverbindung in die Tintenaufnahmeschicht-bildende Lösung hergestellt wird, auf einen Träger.

The invention covers the following aspects:

• (1) An ink jet recording medium comprising a support and an ink receiving layer formed thereon, the inorganic fine particles, a water-soluble aluminum compound, a zirconium compound, a cationically-modified self-emulsifying polymer, a polyvinyl alcohol having a saponification value of 92 to 98 mol% and a crosslinking agent contains.
• (2) A method for producing an ink jet recording medium, comprising preparing a dispersion by collapsing inorganic fine particles and a zirconium compound, or passing inorganic fine particles and a zirconium compound through an opening using a high pressure dispersing apparatus; Preparing an ink receiving layer-forming solution by adding a cationically modified self-emulsifying polymer, a polyvinyl alcohol having a saponification value of 92 to 98 mol, and a crosslinking agent to the dispersion; and forming a coated layer by applying a coating solution prepared by in-line mixing a water-soluble aluminum compound into the ink-receiving layer-forming solution on a support.
• (3) A method for producing an ink jet recording medium, comprising preparing a dispersion by collapsing inorganic fine particles, a zirconium compound and a crosslinking agent or by passing inorganic fine particles, a zirconium compound of a crosslinking agent through an orifice using a high pressure dispersing device; Preparing an ink receiving layer-forming solution by adding a cationically modified self-emulsifying polymer and a polyvinyl alcohol having a saponification value of 92 to 98 mol% to the dispersion; and forming a coated layer by applying a coating solution prepared by in-line mixing a water-soluble aluminum compound into the ink-receiving layer-forming solution on a support.

Detailed description of the invention

following becomes the ink jet recording medium according to the present Invention and the method for producing the same in detail described.

The Ink jet recording medium according to the invention has a support and an ink-receiving layer formed thereon containing inorganic fine particles, a water-soluble aluminum compound, a zirconium compound, a cationic modified self-emulsifying Polymer, a polyvinyl alcohol having a saponification value of 92 to 98 mole% and a crosslinking agent.

following For example, the materials used in the ink jet recording medium will be described can be used according to the invention.

(Cationic Modified Self-emulsifying polymer)

The Ink receiving layer of the ink jet recording medium of the invention includes at least a "cationic modified self-emulsifying polymer "This" cationic modified self-emulsifying polymer Polymers "is one A polymer compound naturally constituting a stable emulsion dispersion in an aqueous Dispersion medium can be obtained without the addition of emulsifier or surfactant Medium or, if used, then only by adding one very small amount. Quantitatively, the above-mentioned "cationic modified self-emulsifying polymers "polymeric substances that have a stable emulsifying ability at a concentration of 0.5 mass% or greater in an aqueous one Dispersing medium at 25 ° C. to have. This concentration is preferably 1% by mass or more and especially preferably 3 Mass% or more.

More specifically, examples of the above-mentioned "cationic modified self-emulsifying polymer" of the invention include, for example, polyaddition or polycondensation-based polymer compounds including cationic groups of primary, secondary or tertiary amine groups or quaternary ones Ammonium groups.

For the above polymers, vinyl polymerization-based polymers obtained by the polymerization of the following vinyl monomers can be used. Examples of the vinyl monomers include: acrylic acid esters and methacrylic acid esters (the ester groups include alkyl or aryl groups which may have substituents, for example the following groups may be employed as alkyl or aryl groups, methyl, ethyl, n-propyl, isopropyl, n- Butyl, sec-butyl, tert -butyl, hexyl, 2-ethylhexyl, tert -octyl, 2-chloroethyl, cyanoethyl, 2-acetoxyethyl, tetrahydrofurfuryl, 5-hydroxypentyl, cyclohexyl, benzyl, hydroxyethyl, 3-methoxybutyl, 2- (2 -Methoxyethoxy) ethyl, 2,2,2-tetrafluoroethyl, 1H, 1H, 2H, 2H-perfluorodecyl, phenyl, 2,4,5-tetramethylphenyl, 4-chlorophenyl);
Vinyl esters, especially vinyl esters of aliphatic carboxylic acids which may have substituents (for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl chloroacetate), aromatic carboxylic acid esters which may have substituents (for example, vinyl benzoate, vinyl 4-methylbenzoate, vinyl salicylate);
Acrylamides especially acrylamide, N-mono-substituted acrylamides, N-di-substituted acrylamides (substituents are alkyl, aryl and silyl groups which may have substituents, for example methyl, n-propyl, isopropyl, n-butyl, tert-butyl, tert-octyl, cyclohexyl, benzyl, hydroxymethyl, alkoxymethyl, phenyl, 2,4,5-tetramethylphenyl, 4-chlorophenyl, trimethylsilyl groups);
Methacrylamides, especially methacrylamide, N-mono-substituted methacrylamides, N-di-substituted methacrylamides (substituents are alkyl, aryl and silyl groups which have substituents, for example methyl, n-propyl, isopropyl, n-butyl, tert-butyl, tert Octyl, cyclohexyl, benzyl, hydroxymethyl, alkoxymethyl, phenyl, 2,4,5-tetramethylphenyl, 4-chlorophenyl and trimethylsilyl groups);
Olefins (for example ethylene, propylene, 1-pentene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, butadiene), styrenes (for example styrene, methylstyrene, isopropylstyrene, methoxystyrene, acetoxystyrene and chlorostyrene), vinyl ethers (for example methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether and methoxyethyl).

at belong to other vinyl monomers for example crotonate ester, itaconate ester, maleate diester, fumarate diester, Methyl vinyl ketone, phenyl vinyl ketone, methoxyethyl vinyl ketone, N-vinyl oxazolidone, N-vinyl pyrrolidone, methylene malononitrile, diphenyl-2-acryloyloxyethyl phosphate, Diphenyl 2-methacryloyloxyethyl phosphate, dibutyl 2-acryloyloxyethyl phosphate, Dioctyl-2-methacryloyloxyethyl and similar.

To the above-mentioned monomers having a cationic group belong to Example of monomers having a tertiary amino group, such as dialkylaminoethyl methacrylates, Dialkylaminoethyl acrylates and the like.

To Polyurethanes that are modified as cationic self-emulsifying Polymers are applicable include for example, polyurethanes obtained by addition polymerization of various combinations of the diol compounds with the diisocyanate compounds listed below be synthesized.

To Specific examples of the above-mentioned diol compound include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 2,2-dimethyl-1,3-propanediol, 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 3,3-dimethyl-1,2-butanediol, 2-ethyl-2-methyl-1,3-propanediol, 1, 2-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanedio1,2,2-diethyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 1,7-heptanediol, 2-methyl-2-propyl-1,3-propanediol, 2,5-dimethyl-2,5-hexanediol, 2-ethyl-1,3-hexanediol, 1,2-octanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, Hydroquinone, diethylene glycol, triethylene glycol, dipropylene glycol, Tripropylene glycol, polyethylene glycols (average molecular weight = 200, 300, 400, 600, 1000, 1500, 4000), polypropylene glycols (mean Molecular weight = 200, 400, 1000), polyester polyols, 4,4'-dihydroxydiphenyl-2,2-propane, 4,4'-dihydroxyphenylsulfone and similar.

To Examples of the above-mentioned diisocyanate compound include methylene diisocyanate, Ethylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-xylylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethylbiphenylene diisocyanate, 4,4'-biphenylene diisocyanate, Dicyclohexylmethane diisocyanate, methylene bis (4-cyclohexyl isocyanate) and the like.

The cationic groups contained in the cationic group-containing polyurethane are cationic groups such as primary, secondary and tertiary amines and quaternary ammonium salts. In the cationic modified self-emulsifying polymer of the invention, a urethane resin having cationic groups such as tertiary amines or quaternary ammonium salts is preferably used. The cationi For example, polyurethane-containing polyurethanes can be obtained by using a material obtained by introducing cationic groups into the above-mentioned diols at the time of synthesizing the polyurethane. Also in the case of the quaternary ammonium salts, polyurethanes containing tertiary amino groups can be quaternized with a quaternizing agent.

The Diol compounds and diisocyanate compounds used for synthesizing of the polyurethane can each be used alone be or they can in combinations of two or more in different proportions dependent on be used for the purpose (for example, control of the glass transition temperature (Tg) of the polymer, solubility improvement, warranty the compatibility with a binder and improving the stability of the dispersion).

When Polyester for the cationic modified self-emulsifying polymer is usable For example, polyesters suitable for polycondensation reactions are suitable various combinations of the diol compounds with the dicarboxylic acid compounds, the ones listed below are to be synthesized.

When above-mentioned dicarboxylic acid compounds are listed oxalic acid, malonic, Succinic acid, glutaric, dimethylmaleic, adipic acid, Pimelic acid, α, α-dimethyl succinic acid, acetodicarboxylic acid, sebacic acid, 1,9-nonanedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, citraconic acid, phthalic acid, terephthalic acid, 2-butylterephthalic acid, tetrachloroterephthalic acid, acetylenedicarboxylic acid, poly (ethylene terephthalate) dicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, ω-poly (ethylene oxide) dicarboxylic acid, p-xylylene dicarboxylic acid and the like.

The above-mentioned dicarboxylic acid compound may, when polycondensed with a diol compound, in Form of an alkyl ester (for example, a dimethyl ester) of a dicarboxylic acid or an acid chloride a dicarboxylic acid can be used or in the form of an acid anhydride such as maleic anhydride, succinic anhydride and phthalic anhydride be used.

When Diol compound can the same compounds are used as diols as they are for the above mentioned polyurethanes have been exemplified.

Of the cationic group-containing esters can be obtained by Synthesis using a dicarboxylic acid compound having a cationic Group like primary, secondary and tertiary Amines and quaternary Ammonium salts.

The the above-mentioned diol compounds, dicarboxylic acids and hydroxycarboxylate ester compounds, used in the synethesis of the polyester can alone be used or they can in combinations of two or more in selected proportions dependent on be used for the purpose (for example, control of the glass transition temperature (Tg) of the polymer, solubility, compatibility with dyes and stability the dispersion).

Of the Content of cationic groups in the cationically modified self-emulsifying Polymer is preferably 0.1 to 5 mmol / g and preferably 0.2 to 3 mmol / g. If the content of cationic groups is too low, decreases the polymer dispersion stability, and if it is too high, the binder compatibility decreases.

The above cationically modified self-emulsifying polymers are preferably polymers which have a cationic group, like a tertiary Amine group or a quaternary Ammonium base, and most preferably these are urethane resins (polyurethane) with a cationic group, similar to the above.

If the above self-emulsifying polymers in an ink receiving layer In particular, their glass transition temperature is used important. After the creation of an image by ink recording is, to the occurrence of bleeding of the image over time suppress, the glass transition temperature of the above self-emulsifying polymer is less than 50 ° C. Farther is the glass transition temperature the self-emulsifying polymer is more preferably at 30 ° C or lower, and particularly preferred is a glass transition temperature of 15 ° C or below. When the glass transition temperature 50 ° C or about that is, the dimensional stability (waves) deteriorates. There are none here special lower limit for the glass transition temperature, however, she lies for normal applications at about -30 ° C and when it is even lower when preparing the aqueous Dispersing the manufacturability can be reduced.

The weight average molecular weight of the self-emulsifying polymer used in the invention is, is usually preferably 1000 to 200000, with 2000 to 50,000 being more preferred. If the molecular weight is less than 1000, there is a tendency that it becomes difficult to add a stable aqueous dispersant receive. When the molecular weight exceeds 200,000, it decreases the solubility, the viscosity the liquid elevated itself and the control of a small mean particle size of the particles of the aqueous Dispersant is difficult, especially the control on 0.05 μm Or less.

Regarding the Amount of the above self-emulsifying polymer used in the Ink absorption layer of the invention is incorporated, this is preferably in the range of 0.1 to 20% by weight in relation to the total solids contents in the structure of the ink receiving layer, wherein 0.3 to 20 mass% is more preferable and 0.5 to 15 mass% most preferred. If the above amount to be incorporated is lower is 0.1 mass%, there is an insufficient improvement in bleeding that with the passage of time occurs. If, on the other hand, the Amount over 30% by mass, the proportion of fine particles or binder components, such as inorganic fine particles and polyvinyl alcohol, lower and lower the ink absorbency in a recording paper of a quality image tends to decrease.

When next the process of preparation of the aqueous dispersion of self-emulsifying Polymer of the invention explained.

The The above-mentioned self-emulsifying polymer is converted into an aqueous Solvent medium mixed in, and to the extent necessary additives are added, and by comminution of the liquid mixture using a dispersing device becomes an aqueous dispersion with a mean particle size of 0.05 μm or below to be obtained. To the watery Different types of dispersion can be obtained known dispersing devices such as the following are used: High-speed Rotationsdispergiervorrichtung, Medium speed dispersing device (such as ball mill, sand mill and Bead mill) Ultrasonic dispersing device, colloid mill dispersing device, high pressure dispersing device. From the perspective of effective dispersion of the lump-like Fine particles is a medium-speed dispersing device preferable, such as a colloid mill dispersing device or high pressure dispersing device.

As a high-pressure disperser (homogenizer) is a detailed mechanism in the patents US 4533254 . JP-A-647264 and the like, however, commercially available devices such as GAULIN HOMOGENIZER (AP V Gaulin Inc.), MICROFLUIDIZER (Microfluidx Inc.), ALTIMIZER (Sugino Machine KK) can be used. A high-pressure homogenizer equipped with a mechanism for forming fine particles in an ultrahigh-pressure nozzle flow, as described in US Pat U.S. Patent 5,720,551 , is particularly effective for the emulsification of the dispersion of the present invention. DeBEE2000 (Bee International Ltd.) is an example of an emulsifier using an ultrahigh pressure nozzle flow.

For the aqueous medium, used in the above dispersing method, water, organic solvent media or mixtures of these media. Suitable organic Solvent media for the Dispersing are: alcohols such as methanol, ethanol, n-propanol, i-propanol and methoxypropanol; Ketones such as acetone, methyl ethyl ketone; tetrahydrofuran, Acetonitrile, ethyl acetate, toluene.

From the above self-emulsifying polymer of the present invention, while a stable emulsion dispersion can be naturally obtained with the polymer itself to accelerate the emulsification of the dispersion and make it more stable, a small amount of dispersant (surfactant) can be used , Various surfactants can be used for this purpose. Preferred examples include anionic surfactants such as fatty acid salts, alkyl sulfate ester salts, alkylbenzenesulfonate salts, alkylnaphthalene sulfonate salts, dialkylsulfosuccinic acid salts, alkyl phosphate ester salts, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl sulfate ester salts, and the like. Further included are nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylamines, glycerol fatty acid esters, oxyethylene-oxypropylene block copolymers, and the like. Further, it is also preferable to use SURFYNOLS (Air Product & Chemicals), an acetylene-based polyoxyethylene oxide surfactant. Further, aminolytic type ampholytic surfactants such as N, N-dimethyl-N-alkylamine oxide and the like are also preferable. Furthermore, the surfactants used in the JP-A-59-157633 (37) to (38) and Research Disclosure No. 308119 (1998).

Around stability can reach directly after emulsification, can also be a water-soluble Polymer added together with the above surfactant become. Preferably used as the water-soluble polymer are polyvinyl alcohols, Polyvinyl pyrrolidone, polyethylene oxide, polyacrylic acid, polyacrylamide and copolymers from that. Furthermore, it is also preferred, of course, available water-soluble polymers such as polysaccharides, casein, gelatin and the like.

at the emulsifying dispersing method mentioned above, is in Dispersion of the above-mentioned self-emulsifying polymer in an aqueous one Medium in particular the control of particle size important. In the production of an image using an ink-jet method it to increase the color purity and color density required, the average Size of the particles the self-emulsifying polymer of the above-mentioned aqueous To keep dispersion small. Especially in the ink-receiving layer According to the invention, it is necessary to increase the mean volume particle size to 0.05 μm or less hold, preferably 0.04 microns or less and where 0.03 μm or less is more preferable.

(Inorganic fine particles)

The Ink-receiving layer according to the present invention contains inorganic fine particles. Examples of the inorganic fine particles belong Silica fine particles, colloidal silica, titania, barium sulfate, calcium silicate, Zeolite, kaolinite, halloysite, mica, talc, calcium carbonate, Magnesium carbonate, calcium sulfate, boehmite, pseudoboehmite. Under fine particles of silica are preferred for these fine particles.

The The above fine silica particles have extremely high specific surface and lead to a layer with a higher Ink absorption and retention capacity. In addition, the silica has a low refractive index, and thus results in dispersion and an appropriate diameter of the fine particles to an ink receiving layer with better transparency and higher color density, and it will a cheap one Coloring achieved. The transparency of the ink receiving layer is important from the standpoint of getting a high color density, coloring property and favorable color gloss, not only for Applications where transparency is required, such as OHP papers and the like, for .... As well Use as recording papers as for photographic gloss papers and similar.

Of the middle primary Particle diameter in the fine inorganic particles is preferably 20 nm or less, more preferably 15 nm or less, and especially preferably 10 nm or less. When the mean primary particle size of the particles 20 nm or less, the ink-absorbing property may be can be effectively improved and at the same time, the shine of the surface the ink receiving layer increases become.

The specific surface area of the inorganic fine particles determined by the BET method is preferably 200 m ² / g or more, more preferably 250 m ² / g or more, and still more preferably 380 m ² / g or more. Inorganic fine particles having a specific surface area of 200 m ² / g or more result in an ink-receiving layer of the image having higher transparency and printing density.

The BET method as used in the present invention is a method for determining the surface of a powder by gas phase adsorption, More specifically, a method of determining the specific surface area d. H. the entire surface per g of a sample, from the absorption isotherm. Nitrogen gas usually becomes used as adsorption gas, and most common is a Method for determining the adsorption amount by the change the pressure or the volume of the adsorbed gas. One of the best Equations that the adsorption isotherm of multimolecular systems is the equation of Brunauer, Emmett and Teller (BET equation). The surface is calculated by multiplying the adsorption amount determined according to the BET equation, with the surface, which is occupied by a single adsorbed molecule.

Especially with fine silica particles, because the surface is silanol groups has a slight adhesion between the particles by the hydrogen bonding of the silanol groups, and there is an adhesion effect between the particles by the silanol groups and the water-soluble resin. Therefore, if the middle primary Size of the particles Is 20 nm or less, the porosity ratio of the ink receiving layer is high, and a structure with high transparency can be achieved and the ink absorption characteristics can be effectively increased.

Fine Silica particles can usually roughly classified into wet process particles and dry process (vapor phase process) Particles according to the manufacturing process. By the wet process For example, fine silica particles are produced mainly by production activated silica by acid decomposition of a silicate, Polymerization of a suitable proportion of the activated silica and coagulating the obtained polymer silica, to get to a hydrated silica. alternative become anhydrous silica particles in the vapor-phase process mainly by high temperature vapor phase hydrolysis of a Silicon halide (flame hydrolysis process) or by reductive Heating and evaporating quartz and coke in an electric furnace by applying an arc discharge and then oxidizing of the vaporized silica with air (arc method). The "vapor-phase silica" results in anhydrous fine silica particles prepared by a vapor phase method.

The vapor-phase silica is different in the density of silanol groups on the surface and by the presence of voids therein, and exhibits different properties of the hydrated silica. The vapor phase process silica is suitable for forming a three-dimensional structure with a higher content of voids. The reason is not clear. In the case of the hydrated silica, the fine particles have a higher density of 5 to 8 silanol groups / nm ² on their surface. As a result, the fine silica particles tend to be tightly coagulated. During the vapor phase process, the silica particles have a lower density of 2 to 3 silanol groups / nm ² on their surface. Thus, vapor-phase silica results in less frequent, softer coagulation (flocculent precipitates), consistently resulting in a higher void percentage structure.

In the present invention, the fine particles of the vapor phase-process silica (anhydrous silica) obtained by the dry method are preferred, the surface of the fine silica particles having a density of 2 to 3 silanol groups / nm ² .

The inorganic fine particles preferably used in the invention are particles of a vapor-phase process silica having a BET specific surface area of 200 m ² / g or more.

(Polyvinyl alcohol)

Of the Polyvinyl alcohol for the insert in the invention has a saponification value of 92 to 98 mol% (hereinafter referred to as "polyvinyl alcohol after the Invention ") Polyvinyl alcohol having a saponification value of less than 92 mol% is not wanted because it does not lead to a halftone image in neutral gray. He leads as well to an increase the viscosity and a deterioration in the coating stability of a Coating solution. On the other hand, a polyvinyl alcohol having a saponification value is also more than 98 mol% not desired, because it leads to a reduction in ink absorption capacity. Of the Saponification value is more preferably 93 to 97 mol%.

Of the Degree of polymerization of the polyvinyl alcohol according to the invention is preferably 1500 to 3600, more preferably 2000 to 3500. A polyvinyl alcohol having a degree of polymerization of more than 1500 results in an ink receiving layer, which is more resistant to breakage. A degree of polymerization of less as 4000 is preferred because such a polyvinyl alcohol to a Reduction of the viscosity the coating solution leads.

A water-soluble resin other than the polyvinyl alcohol of the present invention may be used in combination with the polyvinyl alcohol of the invention. Examples of the water-soluble resins for use in combination include polyvinyl alcohols (PVAs) having a hydroxy group as a hydrophilic structural unit and a saponification value outside the above range, cationically modified polyvinyl alcohols, anionic modified polyvinyl alcohols, silanol-modified polyvinyl alcohols, polyvinyl acetate, cellulose resins (methyl cellulose (MC), Ethylcellulose (EC), hydroxyethylcellulose (HEC), carboxymethylcellulose (CMC), hydroxypropylcellulose (HPC), etc.), chitins, chitosans and starch; hydrophilic resins containing an ether bond such as polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG) and polyvinyl ether (PVE); hydrophilic resins having an amide group or amide bond such as polyacrylamide (PAAM) and polyvinylpyrrolidone (PVP); and similar. Other examples include compounds having a carboxy group as a dissociative group such as polyacrylate salts, maleic acid salts, alginate salts, gelatin and the like. When the polyvinyl alcohol of the invention and the above-described water-soluble resin are used in combination, the proportion of the polyvinyl alcohol of the invention in the total amount of the polyvinyl alcohol of the invention and the water-soluble resin is preferably 1 to 30 Ge % by weight, more preferably 3 to 20% by weight, and still more preferably 6 to 12% by weight.

Around the reduction of the layer strength or a layer break for Time when the layer is dried because of too low Amount of water-soluble To prevent resin and a reduction in ink absorbency To prevent the blockage of the cavities due to the resin is caused too high a content of resin, the content is of the polyvinyl alcohol of the present invention preferably 9 to 40%, more preferably 12 to 33% by mass in relation to the whole Solid mass in the ink receiving layer.

The The above-mentioned polyvinyl alcohol resins contain a hydroxy group as a structural unit. The hydrogen bond between the hydroxy groups and the silanol groups on the surface of the fine silica particles allows the fine silica particles, a three-dimensional Network structure with secondary To form particles as network chain units. The thus formed three-dimensional network structure seems the reason for a lighter Development of an ink receiving layer with a porous structure with a higher one To be void percentage.

In the ink receiving layer absorbs the ink receiving layer, which has a porous structure thus obtained as a result of capillary phenomenon the ink is very fast and leads to printed dots with excellent dot-circle shape without ink bleeding.

<Ratio of Content of inorganic fine particles to polyvinyl alcohol of present invention

The relationship inorganic fine particles (preferably, fine silica particles; x) and polyvinyl alcohol of the invention (when the polyvinyl alcohol used in combinations with another water-soluble resin, the total mass becomes water-soluble Resins represented by "y"), which is included [PB ratio (x / y), mass of inorganic fine particles in relation to 1 particle to the mass of the polyvinyl alcohol of the invention] in the strongest extent also the film structure of an ink receiving layer. That is, if a PB ratio gets bigger, be the porosity, the micropore volume and specific surface area (per unit of mass) greater.

specially is the PB ratio (x / y) preferably 1.5 / 1 to 10/1 from the viewpoint that the reduction the film strength and the break during drying due to a too huge PB ratio is prevented. If the PB ratio is too low, the cavity becomes light filled with a resin and the porosity is reduced, and a reduction in the ink absorption property will be prevented.

at a transport in paper-transporting systems such as inkjet printers For example, a load may be applied to the ink jet recording medium. Therefore, the ink receiving layer should have a sufficiently high layer strength to have. Also from the standpoint of prevention of breakage, peeling or the like the ink receiving layer when the ink jet recording medium in Sheet is cut, the ink-receiving layer should be sufficient have high layer strength. In consideration of the above, the PB ratio is preferably 5/1 or less. On the other hand, on the other hand, an excellent ink absorbing property in inkjet printers, the ratio is more preferably 2/1 or more.

For example, when a coating liquid containing anhydrous silica fine particles having an average primary particle diameter of 20 nm or less and the polyvinyl alcohol of the present invention, and a water-soluble resin is homogeneously mixed in an aqueous solution having a PB ratio (x / y) 2/1 and 5/1 and applied to a support and dried, a three-dimensional network structure with secondary particles of fine silica particles is formed as network chains. Such a coating liquid easily results in a translucent porous layer having an average void diameter of 30 nm or less, a void percentage of 50 to 80%, a void volume of 0.5 ml / g or more, and a specific surface area of 100 m ² / g or more.

(Crosslinking agent)

The Ink-receiving layer according to the present invention contains a crosslinking agent. The ink receiving layer of the invention is preferably one porous Layer of polyvinyl alcohol according to the invention and the water-soluble Resin, if necessary, used in a crosslinking reaction cured by the crosslinking agent.

The above-mentioned crosslinking agent may be suitably selected in proportion to the polyvinyl alcohol of the present invention and the water-soluble resin used if desired, and contained in the ink receiving layer, however, boron compounds are preferable since they allow a faster crosslinking reaction. Examples of the boron compounds include borax, boric acid, borate salts [e.g. Orthoborate salts, InBO ₃ , ScBO ₃ , YBO ₃ , LaBO ₃ , Mg ₃ (BO ₃ ) ₂ and Co ₃ (BO ₃ ) ₂ ,], diborate salts [e.g. Mg ₂ B ₂ O ₅ and Co ₂ B ₂ O ₅ ], metabatate salts [e.g. LiBO ₂ , Ca (BO ₂ ) ₂ , NaBO ₂ and KBO ₂ ] tetrabotassium salts [e.g. Na ₂ B ₄ O ₇ .10H ₂ O], pentaborate salts [e.g. KB ₅ O ₈ .4H ₂ O, Ca ₂ B ₆ O ₁₁ .7H ₂ O and CsB ₅ O ₅ ] and the like. Among them, borax, boric acid and borates are preferable since they are capable of promptly causing a crosslinking reaction. In particular, boric acid or a borate salt is preferable, and the combination of these and polyvinyl alcohol, which is a water-soluble resin, is most preferable.

In In the invention, the above-mentioned crosslinking agent is preferred in an amount of 0.05 to 0.50 parts by weight, in proportion to 1 part by weight of the polyvinyl alcohol of the present invention. preferred is the amount of 0.08 to 0.30 parts by weight. If the amount of inclusion of the crosslinking agent is within the above ranges the polyvinyl alcohol of the present invention is effectively crosslinked and the development of fractures and the like can be prevented.

If Gelatin as water-soluble Resin used in the invention, compounds other than the boron compounds described above as crosslinking agents of water-soluble Resin can be used.

Examples of such crosslinking agents include:
Aldehyde compounds such as formaldehyde, glyoxal and glutaraldehyde; Ketone compounds such as diacetyl and cyclopentanedione; active halogen compounds such as bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1,3,5-triazine and 2,4-dichloro-6-S-triazine sodium salt; active vinyl compounds such as divinylsulfonic acid, 1,3-vinylsulfonyl-2-propanol, N, N'-ethylenebis (vinylsulfonylacetamide) and 1,3,5-triacryloylhexahydro-S-triazine; N-methylol compounds such as dimethylolurea and methyloldimethylhydantoin; Melamine resin such as methylol melamine and alkylated methylol melamine; epoxy resins;
Isocyanate compounds such as 1,6-hexamethylene diisocyanate; Aziridine compounds, such as those described in US 3017280 and 2983611 ; Carboxyimide compounds such as those in US 3100704 are described; Epoxy compounds such as glycerol triglycidyl ether; Ethyleneimino compounds such as 1,6-hexamethylene-N, N'-bisethyleneurea; halogenated carboxyaldehyde compounds such as mucochloric acid and mucophenoxychloric acid; Dioxane compounds such as 2,3-dihydroxydioxane; metal-containing compounds such as titanium lactate, aluminum sulfate, chrome alum, potassium alum, zirconyl acetate and chromium acetate; Polyamine compounds such as tetraethylenepentamine; Hydrazide compounds such as adipic dihydrazide; and low molecular weight compounds or polymers containing at least two oxazoline groups. These crosslinking agents may be used alone or in combination of two or more thereof.

(Water-soluble aluminum compound)

The Ink-receiving layer according to the invention contains a water-soluble aluminum compound. The Presence of a water-soluble Aluminum compound is effective for improving water resistance and the resistance against ink bleeding during a long storage time of the generated image.

To Examples of water-soluble Aluminum compounds include inorganic salts such as aluminum chloride or its hydrates, aluminum sulfate or its hydrates, ammonium alum and the like. For other examples belong inorganic aluminum-containing cationic polymers such as basic Polyaluminum. Among these are basic polyaluminum hydroxide compounds prefers.

The above basic polyaluminum hydroxide compounds are water-soluble polyaluminum hydroxide compounds stably containing polynuclear condensate ions of basic polymers such as [Al ₆ (OH) ₁₅ ] ³⁺ , [Al ₈ (OH) ₂₀ ] ⁴⁺ , [Al ₁₃ (OH) ₃₄ ] ⁵⁺ , [Al ₂₁ (OH) ₆₀ ] ^{3 +} , and the main components thereof are represented by the following formulas. [Al ₂ (OH) _n Cl _6-n ] _m 5 <m <80, 1 <n <5 Formula 1 [Al (OH) ₃ ] _n AlCl ₃ 1 <n <2 Formula 2 Al _n (OH) _m Cl _(3n-m) 0 <m <3n, 5 <m <8 Formula 3

These Compounds with different degrees of purity can be easily obtained and are on the market by Taki Chemical Co. ltd. as polyaluminum chloride (PAC) as water treatment agent, by Asada Kagaku Co. Ltd. when polyhydrated aluminum (Paho) also by Rikengreen Co. Ltd., as Pyurakem WT, Taimai Chemicals Co. Ltd., as Alphaine 83 and from other manufacturers for available for the same purpose. For the invention is it suitable, commercially available To use products directly because there are, however, materials unsuitable low pH, it is possible in these cases, in suitable to adjust the pH.

Of the Content of water-soluble Aluminum compound in the ink receiving layer of the invention is preferably 0.1 to 20% by weight, more preferably 1 to 8% by weight and most preferably 2 to 4% by weight, based on the total Solids in the ink receiving layer. A content of water-soluble Aluminum compound in the range of 2 to 4% by weight is effective for the Improvement of gloss of water resistance, gas resistance and the light stability.

(Zirconium compound)

The Ink-receiving layer according to the invention contains a zirconium compound. The use of the zirconium compound allows an improvement the water resistance.

For the zirconium compound in use for The invention is not particularly limited, and various ones may be used Connections are used. Typical examples include zirconyl acetate, Zirconium chloride, zirconium oxychloride, zirconium hydroxychloride, Zirconium nitrate, basic zirconium carbonate, zirconium hydroxide, Zirconium ammonium carbonate, zirconium potassium carbonate, zirconium sulfate, Zirconium fluoride and the like. Zirconyl acetate is particularly preferred.

Of the Content of the zirconium compound in the ink receiving layer after of the invention preferably 0.05 to 5.0% by weight, more preferably 0.1 to 3.0% by weight and most preferably 0.5 to 2% by weight based on the total Solids in the ink receiving layer. A content of zirconium compound in the range of 0.5 to 2% by weight allows an improvement in the water resistance without deterioration for the ink absorption efficiency.

For the invention can a water-soluble polyvalent metal compound, other than the water-soluble aluminum compound, and the zirconium compound described above can be used in combination. Examples of other water-soluble polyvalent metal compound belong water-soluble salts of a metal, selected calcium, barium, manganese, copper, cobalt, nickel, iron, zinc, Chromium, magnesium, tungsten and molybdenum.

To typical examples include Calcium acetate, calcium chloride, calcium formate, calcium sulfate, barium acetate, Barium sulfate, barium phosphate, manganese chloride, manganese acetate, manganese formate dihydrate, Manganese ammonium sulfate hexahydrate, copper (II) chloride, ammonium copper (II) chloride dihydrate, Copper sulfate, cobalt chloride, cobalt thiocyanate, cobalt sulfate, nickel sulfate hexahydrate, Nickel Chloride Hexahydrate, Nickel Acetate Tetrahydrate, Nickel Ammonium Sulfate Hexahydrate, Nickel amidosulfate tetrahydrate, iron (II) bromide, ferrous chloride, Iron (III) chloride, iron (II) sulfate, iron (III) sulfate, zinc bromide, Zinc chloride, zinc nitrate hexahydrate, zinc sulfate, chromium acetate, chromium sulphate, Magnesium sulfate, magnesium chloride hexahydrate, magnesium citrate nonahydrate, Sodium phosphotungstate, sodium tungsten citrate, dodecatungstophosphoric acid n-hydrate, Dodecawolframokieselsäure-26-hydrate, Molybdenum chloride, Dodecamolybdänophosphorsäure n-hydrate and similar.

(Other components)

In addition is the ink receiving layer of the present invention is constructed It may contain the following components if necessary is.

Around To limit deterioration of the ink dye, anti-fading agents be included, such as different ultraviolet absorbers, Contains antioxidants and repellents for singlet oxygen.

Examples of ultraviolet absorbers include cinnamic acid derivatives, benzophenone derivatives and benzotriazolylphenol derivatives. Specific examples are α-cyanophenyl cinnamic acid butyl ester, o-benzotriazolbenzene, o-benzotriazole p-chlorophenol, o-benzotriazole-2,4-di-t-butylphenol, o-benzotriazole-2,4-di-t-octylphenol. A hindered phenolic compound can also be used as an ultraviolet absorbent, and phenol derivatives in which at least one or more of the 2-position and / or 6-position are substituted by a branched alkyl group are preferred.

Also, an ultraviolet absorber based on benzotriazole, an ultraviolet absorber based on salicylic acid, an ultraviolet absorber based on a cyanoacrylate, and an ultraviolet absorber based on an oxalic acid anilide may be used. For example, the ultraviolet absorbers may be used as described in US Patent No. 4,729,854 JP-A No. 47-10537 . 58-111942 . 58-212844 . 59-19945 . 59-46646 . 59-109055 and 63-53544 , Japanese Patent Publication ( JP-B) No. 36-10466 . 42-26187 . 48-30492 . 48-31255 . 48-41572 and 48-54965 . 50-10726 . U.S. Patent No. 2,719,086 . 3707375 . 3754919 , and 4220711 or similar.

An optical brightener may also be used as an ultraviolet absorber, and specific examples include an optical brightener based on coumarin. Specific examples are described in JP-B-45-4699 and 54-5324 or similar.

Examples of antioxidants are described in EP 223739 . 309401 . 309402 . 310551 . 310552 and 459416 . DE Patent No. 3435443 . JP-A No. 54-48535 . 60-107384 . 60-107383 . 60-125470 . 60-125471 . 60-125472 . 60-287485 . 60-287486 . 60-287487 . 60-287488 . 61-160287 . 61-185483 . 61-211079 . 62-146678 . 62-146680 . 62-146679 . 62-282885 . 62-262047 . 63-051174 . 63-89877 . 63-88380 . 66-88381 . 63-113536 .
63-163351 . 63-203372 . 63-224989 . 63-251282 . 63-267594 . 63-182484 . 1-239282 . 2-262654 . 2-71262 . 3-121449 . 4-291685 . 4-291684 . 5-61166 . 5-119449 . 5-188687 . 5-188686 . 5-110490 . 5-1108437 and 5-170361 . JP-B No. 48-43295 and 48-33212 . U.S. Patents 4,814,262 and 4980275 ,

To specific examples of the antioxidants include 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2,3,4, -tetrahydrochinolin, Nickel cyclohexanoate, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2-ethylhexane, 2-methyl-4-methoxy-diphenylamine, 1-methyl-2-phenylindole.

These Anti-fading agents can used alone or in combination of two or more. The anti-fading agent can dissolved in water, dispersed, emulsified, or incorporated into microcapsules become. The amount of the anti-fading agent added is preferably 0.01 to 10% by mass, based on the total coating liquid the ink recording layer.

Around to prevent a wave is going for the invention prefers, organic solvents with a high Include boiling point in the ink receiving layer.

For the above water-soluble preferred high-boiling organic solvents. When water-soluble organic solvents with high boiling points, examples are the following alcohols: ethylene glycol, Propylene glycol, diethylene glycol, triethylene glycol, glycerol, diethylene glycol monobutyl ether (DEGMBE), Triethylene glycol monobutyl ether, glycerol monomethyl ether, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,4-pentanetriol, 1,2,6-hexanetriol, thiodiglycol, Triethanolamine, polyethylene glycol (average molecular weight less as 400). Diethylene glycol monobutyl ether (DEGMBE) is preferred.

The Amount of high-boiling organic solvents mentioned above, in the coating liquid for the Ink receptive layer can be used, is preferably 0.05 to 1 mass%, wherein particularly preferably 0.1 to 0.6% by mass.

For the increase of Dispersibility of inorganic fine particles may be inorganic Salts and acids or alkali for the pH adjustment can be included.

Farther can be included to induce frictional charge and Abblätterungsladung on the surface to prevent conductive fine metal oxide particles and matting agents to the surface friction to reduce.

(Carrier)

As the carrier, both transparent carriers of a transparent material such as plastic and opaque carriers of an opaque material such as paper can be used. The use of a transparent A carrier or an opaque glossy carrier is preferred for producing as much transparency as possible of the ink receiving layer. It is also possible to use a write-protected optical disk such as a CD-ROM or DVD-ROM, a write-once optical disk such as a CD-R or a DVD-R or a rewritable optical disk as a carrier, and to apply an ink receiving layer to the recording surface thereof produce.

Material, which is transparent and can tolerate radiant heat if it is used at OHP's, and a backlight display is preferable as a material for the above said transparent support used can be. Examples of the material include polyesters such as polyethylene terephthalate (PET); Polysulfone, polyphenylene oxide, polyimide, polycarbonate and Polyamide. The polyesters are preferable among these and, in particular Polyethylene terephthalate is preferred.

For the thickness of the transparent carrier there is no particular restriction however, a thickness of 50 to 200 microns is because of the easier usability prefers.

One opaque carrier with high gloss, whose surface, on which the ink receiving layer is formed, a gloss level of 40% or more is more preferable. The gloss level is a value which is determined by the method described in JIS P-8142 (paper and board grade 75 method for testing the mirrored gloss level). Specific examples of such carriers include the following carriers.

To Examples include paper carrier with high gloss like art paper, coated paper, cast brushed (Glossy) Paper and baryta paper used as a carrier for silver salt photography used or similar; Polyester such as polyethylene terephthalate (PET), cellulose esters such as Nitrocellulose, cellulose acetate and cellulose acetate butyrate, opaque High gloss foils consisting of enclosed white pigments or similar in plastic films such as polysulfone, polyphenylene oxide, polyimide, polycarbonate and polyamide (wherein a surface calendering treatment is performed can); or carrier, in which a coating layer of polyolefin is produced, that either a white pigment contains or none, on the surface of various paper carriers is generated, transparent carrier or a glossy film containing a white pigment or the like contains.

white pigment containing foam polyester films (for example a foam PET, containing the fine polyolefin and in which by pulling cavities are formed) is also preferred. Furthermore, it is suitable a resin-coated paper used for a printing paper for silver halide photography is used.

The Thickness of the opaque carrier is not particularly limited. However, a thickness of 50 to 300 μm becomes easier for handling prefers.

The surface of the carrier Can by corona discharge treatment, glow discharge treatment, flame treatment or ultraviolet radiation treatment or the like, so that the wetting and adhesion properties are improved become.

When next the base paper is described for the paper carrier as a resin-coated paper is used.

The Base paper consists mainly of a wood pulp and is made using a synthetic pulp like polypropylene, in addition to the wood pulp if necessary, or of a synthetic one Fiber such as nylon or polyester. LBKP, LBSP, NBKP, NBSP, LDP, NDP, LUKP and NUKP can be used as wood pulp. Preferably, they are more commonly used LBKP, NBSP, LBSP, NDP and LDP containing a proportion of short fibers contain. The relationship of LBSP and / or LDP is preferably in the range between 10 Mass% and 70 mass%.

One chemical pulp with few impurities (sulphate pulp and sulfite pulp) is preferably used as pulp, and a pulp in which the whiteness is improved by Bleaching is useful.

glues like higher ones fatty acids and alkylketene dimers, white pigments such as calcium carbonate, talc and titanium dioxide, paper reinforcing agents like strength, Polyacrylamide and polyvinyl alcohol, optical brightening agents, Water repellents such as polyethylene glycols, dispersants and emollients such as quaternary ammonium may be present in be suitably added to the base paper.

Of the freeness of the pulp for the paper production is preferably 200 to 500 ml as stated by CSF. The sum 24 mesh (mesh size) residue and 42 mesh residues is preferably 30 to 70% by mass as stated in JIS P-8207. 4 mesh residues are preferably 20% by mass.

The basis weight of the base paper is preferably 30 to 250 g, and more preferably 50 to 200 g. The thickness of the base paper is preferably 40 to 250 μm. A high softness can be imparted to the base paper by calendering in the papermaking stage or after papermaking. The density of the base paper is generally 0.7 to 1.2 g / m ² (JIS P-8118). In addition, the strength of the base paper is preferably 20 to 200 g under the conditions of JIS P-8143.

On the surface of the base paper can be a surface active Means are applied, and a glue, which is the same as glue added to the base paper can be used as a surface sizing agent be used. It is preferred that the pH of the base paper 5 to 9, when using the hot water extraction method measured by JIS P-8113.

in the general can Both the top and the back of the base paper with Polyethylene coated. Main examples of polyethylene belong Low density polyethylene (LDPE) and / or polyethylene with high density (HDPE), it can however, some others such as LLPDE and polypropylene are also used become.

Especially in the polyethylene layer on the side on which the ink receiving layer It is preferred that rutile type titanium oxide or Anatase type, optical brightener or ultramarine blue pigment be added to the polyethylene and thereby the degree of opacity, the whiteness and the tint improve as is for Printing papers for Photographs to a large extent is carried out. The content of titanium oxide is preferably about 3 to 20% by mass, more preferably 4 to 13% by mass to Polyethylene. The thickness of the polyethylene layer is not on one limited special thickness, and it is more preferably 10 to 50 microns. Farther For example, a subbing layer may be formed to enhance adhesion of the ink receiving layer on the polyethylene layer to improve. water-soluble Polyester, gelatin and PVA are preferably used as underlayer. The thickness of the underlayer is preferably 0.01 to 5 microns.

One polyethylene coated paper sheet can be used as glossy paper be, or if polyethylene on the surface of the base paper sheet is applied by melt extrusion, a matte surface or silky finish can be generated by applying a Gaufrage treatment, as in conventional photographic printing paper sheets is obtained.

On the carrier body can a back Be provided coating layer, and white pigments, water-soluble binder and other components can as additional Components for the back backing be used.

To Examples of the white pigment, that in the back Coating layer is included include inorganic white pigments such as calcium carbonate, calcium carbonate, kaolin, talc, Calcium sulfate, barium sulfate, titanium oxide, zinc oxide, zinc sulfide, zinc carbonate, Satin white, Aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudo-boehmite, aluminum hydroxide, alumina, Lithopone, zeolite, hydrated halloysite, magnesium carbonate and magnesium hydroxide; as well as organic pigments as on styrene based plastic pigments, acrylic-based plastic pigments, Polyethylene, microcapsules, urea resin and melamine resin.

To Examples of the aqueous Binders for the back Coating layer can be used include water-soluble polymers such as styrene / maleic acid copolymer, styrene / acrylate copolymer, Polyvinyl alcohol, silanol-modified polyvinyl alcohol, starch, cationic Strength, Casein, gelatin, carboxymethylcellulose, hydroxyethylcellulose and polyvinylpyrrolidone; and water-dispersible polymers such as Styrene-butadiene latex and acrylic emulsions.

To other components included in the backside coating layer can be included belong defoamers, Foam suppressants, Dyes, optical brighteners, preservatives and water-proofing agents.

The first method of manufacturing an ink jet recording medium of the invention summarizes the preparation of a dispersion by collapsing inorganic fine particles and a zirconium compound or by passing inorganic fine particles and a zirconium compound through an orifice using a high pressure disperser; Preparing an ink receiving layer-forming solution by adding a cationic modified self-emulsifying polymer, a polyvinyl alcohol having a saponification value of 92 to 98 mol%, and a crosslinking agent to the dispersion; and forming a coated layer by applying a coating solution prepared by in-line mixing a water-soluble aluminum compound into the ink-receiving layer-forming solution on a support.

alternative for this, the second method comprises manufacturing an inkjet recording medium according to the invention, the preparation of a dispersion by colliding inorganic fine particles, a zirconium compound and a Crosslinking agent or by guiding inorganic fine particle, a zirconium compound of a crosslinking agent through an opening using a high pressure disperser; Produce an ink-receiving layer-forming solution by adding a cationic modified self-emulsifying polymers and a polyvinyl alcohol having a saponification value of 92 to 98 mol% to the dispersion; and forming a coated layer by applying a coating solution comprising by in-line mixing of a water-soluble aluminum compound into the ink receiving layer forming solution a carrier.

The Inkjet recording medium according to the invention can be achieved by the first or by the second method of manufacturing an ink jet recording medium produced according to the invention.

The Dispersion obtained by colliding "inorganic fine particles and a zirconium compound "or" inorganic fine particles, a zirconium compound and a crosslinking agent "or by guiding" inorganic fine particles and a zirconium compound "or" inorganic fine particles, a zirconium compound and a crosslinking agent "through an opening below Using a Hochdruckdispergiervorrichtung is advantageous in that they have inorganic fine particles with a lower Contains particle diameter.

The Mixture of "inorganic fine particles and a zirconium compound "or" inorganic fine particles, a zirconium compound and a crosslinking agent is introduced into a high pressure disperser introduced, when it is in a dispersed (coarsely dispersed) state. The provisional Mixing (coarse dispersion) can be carried out by means of a customary propeller, turbine stirrer, Homogenizer or similar.

The High pressure dispersing device for the use in the dispersion is generally favorable a commercially available Device referred to as a high-pressure homogenizer.

To typical examples of high pressure homogenizers include nanomizers (Trade name, manufactured by Nanomizer), Microfluidizer (Trade name, manufactured by Nicrofluidex Inc.), Ultimizer (manufactured from Sugino Machine Ltd.) and the like.

The opening is a mechanism that restricts the flow of liquid that passed through a straight tube to a thin plate, the inserted therein has fine circular openings (throttle disc).

Of the High pressure homogenizer is a device that works in its basic building blocks from a high pressure generating unit for the pressure treatment of the Example of a slurry a raw material, and an opening unit or unit for colliding. In general, will a high-pressure pump, which is referred to as a plunger pump, advantageous used in the high pressure generating unit. It can be different Types of high pressure pumps, single pumps, double pumps, triple pumps and others for the invention without limitation be used.

If the particles are treated by colliding at high pressure, is the pressure is preferably 50 MPa or more, more preferably 100 MPa or more and more preferably 130 MPa or more.

The Pressure difference between the inlet and the outlet of the opening during the Treatment is also preferably 50 MPa or more, more preferably 100 MPa or more and more preferably 130 MPa or more, similar to the above process pressure.

The Collision speed during of colliding the pre-emulsion is preferably 50 m / sec or more and more preferably 150 m / sec or more than relative speed.

The linear velocity of a solvent passed through the aperture may vary depending on the pore size of the opening used vary, However, it is preferably 50 m / sec or more, more preferably 100 m / sec or more and more preferably 150 m / sec or more, similar to the collision speed when colliding.

at depends on any method the dispersion efficiency from the process pressure, and a higher one Process pressure leads to a higher one Dispersion efficiency. However leads a process pressure of more than 350 MPa is often related to problems on the pressure resistance the piping of the high pressure pump and the durability of the device.

at Any of the methods described above is the frequency The procedure is not particularly limited and will normally in the range of once to twelve times carried out. The dispersion is prepared in this way.

It can various additives are added in the preparation of the dispersion become.

To Examples of additives include various nonionic or cationic surfactants (anionic surfactant Funds are undesirable because of aggregation), antifoam, nonionic hydrophilic Polymers (polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, Polyacrylamide, various sugars, gelatin, pullulan, etc.), nonionic or cationic latex dispersions, water-miscible organic solvent (Ethyl acetate, methanol, ethanol, isopropanol, n-propanol, acetone, etc.), inorganic Salts, pH adjusting agents and the like, these additives are used when needed.

Especially are desirable water-miscible organic solvents that cause microaggregation of fine inorganic particles (silica) during the Prevent predispersion. The water-miscible organic solvent is used in an amount of 0.1 to 20% by weight, with particular preference preferably 0.5 to 10% by weight in the dispersion.

Of the pH during the preparation of the dispersion with inorganic fine particles (Vapor-phase process silica) can vary significantly, for example according to the nature of the inorganic fine particles (vapor phase method silica), which are used, and because of various added additives, however, it is generally from 1 to 8, more preferably 2 to

7th Two or more additives can used in combination in the dispersion.

at the method for producing an ink jet recording medium according to the invention For example, a solution forming the ink receiving layer is prepared by adding a cationically modified self-emulsifying polymer, a Polyvinyl alcohol according to the invention and the like to the above dispersion obtained. The one described above Dispersion, the cationically modified self-emulsifying polymers, the polyvinyl alcohol of the invention and others can be mixed for example, by usual Propeller mixture, turbine mixture or homogenizer mixture.

In the method for producing an ink-jet recording medium of the invention, examples of in-line mixers which are preferably used in in-line mixing of the water-soluble aluminum compound in the solution forming the ink receiving layer are, but are not limited to, those described in U.S. Pat JP-A-2,002 to 85,948 are described as well as others.

The Method for producing an ink jet recording medium according to the invention Further, the crosslinking and curing of the applied layer include on a carrier was formed by applying the coating solution obtained was by in-line mixing of a water-soluble aluminum compound into the solution, which forms the ink receiving layer by applying one to it basic solution with a pH of 7.1 or more, either (1) simultaneously with the Applying the coating solution or (2) before the applied layer has a falling rate of drying while the drying of the applied layer shows.

The presence of such a crosslinked cured ink receiving layer is preferred Point of the ink absorption capacity and the fracture resistance of the layer.

at the method for producing an ink jet recording medium according to the invention may include water, an organic solvent or a solvent mixture of which as a solvent be used in every stage. Examples of organic solvents for use in the coating include alcohols such as methanol, Ethanol, n-propanol, i-propanol and methoxypropanol, ketones such as acetone and methyl ethyl ketone, Tetrahydrofuran, acetonitrile, ethyl acetate, toluene and the like.

The coating solution the ink receiving layer can be applied by known methods, as using an extrusion die coater, air knife coater, a doctor coater, a bar coater, a knife coater, a press-coater, a co-rotating roll coater or a bar coater.

The basic solution with a pH of 7.1 or more is applied to the applied layer, produced by applying the solution forming the ink receiving layer is, simultaneously with the application of the ink receiving layer forming solution applied or before the applied layer a falling rate of drying while the drying of the coated layer shows. This will be the hardened Layer advantageous by applying the basic solution with formed at a pH of 7.1 or more on the coated layer, while they have a constant drying rate after application the solution forming the ink receiving layer shows.

The basic solution with a pH of 7.1 or more may be a crosslinking agent and others as required. The basic solution with a pH of 7.1 or more accelerates the cross-linking than alkaline solution, and this amounts to the pH of which is preferably 7.5 or more, more preferably 7.9 or more. A pH closer to the acidic side, insufficient crosslinking of the polyvinyl alcohol, in which the ink-receiving layer-forming solution is contained, through the Cause crosslinking agents, causing problems like tanning, Breakage of the ink receiving layer and others leads.

The basic solution having a pH of 7.1 or more is produced, for example Addition of a metal compound (eg 1 to 5%) and a basic Compound (eg 1 to 5%) and also of p-toluenesulfonic acid (eg. B. 0.5 to 3%) as required to ion-exchanged water and intimate stirring of the mixture. "%" Above for each component means% by weight the solids.

Of the Term "before the coated layer has a falling rate of drying shows "usually means a period of a few minutes after the application of the coating solution for the ink receiving layer, while the coated layer the appearance of the "constant Drying rate "shows the content of the solvent (Dispersion medium) drops linearly over time. Of the Period of this "constant Drying speed "is for example, described in Chemical Engineering Handbook (p. 707 to 712, published by Maruzen Co. Ltd., October 25, 1980).

The Solution, which forms the ink receiving layer generally after application at 40 to 180 ° C for 0.5 to 10 minutes (preferably for 0.5 to 5 minutes) until the coated layer has a falling drying rate as described above. Of the Drying period varies of course dependent on from the applied amount, but is preferably in the above Area.

The inorganic fine particles in the ink recording medium of the invention may be fine silica particles, and the fine silica particles may be vapor-phase silica particles having a BET specific surface area of 200 m ² / g or more.

Of the Degree of polymerization of the polyvinyl alcohol used in the ink recording medium according to The invention may be 1500 to 3600.

In The ink-jet recording medium of the invention can use the water-soluble Aluminum compound also a basic polyaluminium hydroxide compound be. In the ink starling recording medium According to the invention, the zirconium compound may also zirconyl acetate be.

In The inkjet recording medium according to the invention can use the Self-emulsifying polymers also have a urethane resin with a cationic Be a group.

In the ink jet recording medium of the invention, the crosslinking agent may also be boron acid or a borate salt.

The Method for producing an ink jet recording medium according to the invention can the extra Networking and curing the coated layer by applying a basic solution with a pH of 7.1 or more on it, either (1) simultaneously with the application of the coating solution or (2) before the coated Layer a falling rate of drying during drying the coated layer shows.

Examples

following The present invention will be explained in more detail with reference to FIGS Examples are described, but this is to be understood that the The invention is not limited to the following examples. "Parts" and "%" in the following Examples relate to parts by weight.

[Example 1]

"production of the carrier "

50 Parts acacia LBKP and 50 parts aspen LBKB were up to a Canadian one freeness of 300 ml in a Scheibenaufschläger pitched to a Holzfaseraufschlämmung to get.

Subsequently were 1.3% cationic starch (CAT 0304L, manufactured by Japan NSC), 0.15% of an anionic Polyacrylamide (Polyacron ST-13, manufactured by Saiko Chemicals Co. Ltd.), 0.29% of an alkyl ketene dimer (sizepine K) from Arakawa Chemical Industries, Ltd.), 0.29% epoxidized amide behenate, 0.32% polyamide-polyamine-epichlorohydrin (Arafix 100, manufactured by Arakawa Chemical Industries, Ltd.) and then 0.12% of an antifoam agent with respect to the pulp added to the obtained pulp slurry.

The pulp slurry prepared above is then converted into paper using a Fourdrinier paper machine, and in a drying process, the felt surface of the web is pressed against the cylinder of a tumble dryer by means of a dryer cloth, with the tension of the dryer cloth set to 1.6 kg / cm , After drying, the base paper was treated in a size press on both sides with polyvinyl alcohol (trade name: KL-118, manufactured by Kuraray Company Ltd.) at a coating amount of 1 g / m ² , dried and calendered. The basis weight of the sheet-shaped base paper was 157 g / m ² , and a base paper (base material) having a thickness of 157 μm was obtained.

After electric corona discharging treatment of the wire surface (back surface) of the base material, a mixture of low and high density polyethylene resins was melt extruded in a ratio of 80% / 20% to a dry weight of 20 g / m ² on the wire facing surface (back surface) of the Base material using a melt extruder at a temperature of 320 ° C. to obtain a thermoplastic layer on a paper web surface (hereinafter, referred to as a "back surface") The thermoplastic resin layer on the back surface was further treated with a corona discharge, and Subsequently, a dispersion containing alumina ("Alumina Sol 100" manufactured by Nissan Chemical Industries Co., Ltd.) and silica ("Snowtex O" manufactured by Nissan Chemical Industries Co., Ltd.) was used as antistatic agents in U.S. Patent No. 4,134,654 Water with a quantity of 1: 2 weight dispersed, and applied to it with a dry weight of 0.2 g / m ² . Subsequently, the surface was corona treated, and a polyethylene having a density of 0.93 g / m ² containing 10% by weight of titanium dioxide was applied thereon at a dry weight of 24 g / m ² at 320 ° C using a melt extruder.

<production the solution A for the Formation of ink-receiving layer>

Corresponding the following "silica dispersion A "composition For example, fine silica particles were added to a liquid containing dimethylallyl-ammonium chloride polymer (Shallol DC 902P, manufactured by Dai-Ichi Kogyo Seiyaku) in internally exchanged Water. This was Zircosol ZA-30, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd. and the resulting slurry was added in an Ultimizer manufactured by Sugino Machine Ltd. at 170 MPa dispersed to arrive at the silica dispersion A, which Particles with a mean diameter (mean particle diameter) of 120 nm.

Corresponding the following composition of the solution A for the formation of the ink receiving layer were ion-exchanged water, 7.5% boric acid solution, SC-505, polyvinyl alcohol solution and Superflex 650-5 to the silica dispersion A in this order to add to a solution A forming the ink receiving layer reach.

"Siliciumdioxiddisperion A "

• (1) Fine silica particles of vapor phase method 15.0 parts (Aerosil 300SF75, manufactured by Nippon Aerosil Co., Ltd.)
• (2) Ion-exchanged water 82.9 parts
• (3) "Shallol DC 902P "(51.5% Solution) 1.31 parts (dispersant, manufactured by Dai-Ichi Kogyo Seiyaku Co., Ltd.)
• (4) Zirconyl acetate "Zircosol ZA-30 (50% solution) "0.81 parts (prepared by Daiichi Kigenso Kagaku Kogyo Co., Ltd.)

"Composition the solution forming the ink-receiving layer A "

• (1) Silica dispersion A 59.5 parts
• (2) Ion-exchanged water 7.8 parts
• (3) 7.5% boric acid solution (crosslinking agent) 4.4 parts
• (4) Dimethylamine-epichlorohydrin-polyalkylene-polyamine polycondensate (50%) Solution) (SC 505, manufactured by Hymo Co., Ltd.) 0.1 parts
• (5) The following polyvinyl alcohol solution 26.0 parts
• (6) Cationic modified polyurethane 2.2 parts [Superflex 650-5 (25% solution)] (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)

<composition the polyvinyl alcohol solution>

• (1) Polyvinyl alcohol 6.96 parts ("JM-23 (DLL)" produced from Japan VAM & POVAL Co., Ltd., saponification value: 93.2 mol%, degree of polymerization: 2400)
• (2) Polyoxyethylene lauryl ether 0.23 parts (surfactant Agent, Emulgen 109P, manufactured by Kao Corp.)
• (3) Diethylene glycol monobutyl ether 2.12 parts (butycenol 20P, manufactured by Kyowa Hakko Kogyo Co., Ltd.)
• (4) Ion-exchanged water 90.69 parts.

(Preparation of Inkjet Recording Sheet)

The front side of the above substrate was treated with corona discharge; Solution A for the formation of the ink receiving layer and the following solution PAC 1 were mixed in-line and coated thereon in coating amounts of 183 g / m ² and 11.4 g / m ² , respectively, using an extrusion die coater. Subsequently, the coated layer was dried in a hot air dryer at 80 ° C (flow rate: 3 to 8 m / sec) to a solids concentration of 20%. The applied layer showed a constant rate of drying during this period. The coated layer was then immersed in a basic solution (pH: 7.8) having the following composition for three seconds before showing a falling rate of drying, whereby the deposition of the solution on the coated layer was in an amount of 13 g / m ² was possible. This was dried at 65 ° C for 10 minutes (hardening step) to obtain an ink jet recording sheet of Example 1, which carried an ink receiving layer having a dry film thickness of 32 μm.

<Solution PAC 1>

• (1) Aqueous polyaluminum with a basicity of 83% (Alfine 83, manufactured by Taimei Chemicals Co., Ltd. Co.) 20 parts
• (2) Ion-exchanged water 80 parts

<composition the basic solution>

• (1) boric acid 0.65 parts
• (2) Zirconium ammonium carbonate (28% aqueous solution) 0.33 parts (Zircosol AC-7, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.)
• (3) Ammonium carbonate (reagent grade) 3.5 parts (manufactured by Kanto Kagaku Co. Inc.)
• (4) Interior exchanged water 63.3 parts
• (5) Polyoxyethylene lauryl ether (2% aqueous solution) 30.0 parts (Surfactant Agent, Emulgen 109P, manufactured by Kao Corp.)

[Example 2]

One Ink jet recording sheet of Example 2 became more similar A method as prepared in Example 1, except that the in the solution A for the Forming the ink receiving layer used polyvinyl alcohol replaced was prepared by another polyvinyl alcohol (Denka POVAL H-24 by Denki Kagaku Kogyo K.K., saponification value 95.6 mol%, degree of polymerization: 2400).

[Example 3]

One Ink jet recording sheet of Example 3 became more similar A method as prepared in Example 1, except that the in the solution A for the Forming the ink receiving layer used polyvinyl alcohol replaced was replaced by another polyvinyl alcohol (JM23, manufactured by Japan VAM & POVAL Co., Ltd., saponification value 96.8 mol%, degree of polymerization: 2400).

[Example 4]

One Ink jet recording sheet of Example 4 became more similar A method as prepared in Example 1, except that the in the solution A for the Forming the ink receiving layer used polyvinyl alcohol replaced was replaced by another polyvinyl alcohol (JM-33, manufactured by Japan VAM & POVAL Co., Ltd., saponification value 94.3 mol%, degree of polymerization: 3300), and the process of "producing the Ink jet recording sheet "mentioned in Example 1 became by the following method "Production of the ink jet recording sheet ".

(Preparation of Inkjet Recording Sheet)

The front side of a support was treated by corona discharge as in Example 1, and the solution for the formation of the ink receiving layer and the solution PAC 1 were mixed in-line and thereon in coating amounts of 183 g / m ² and 11.4 g / m ^2, respectively applied using an extrusion die coater. The support was then treated in a cold air dryer at 5 ° C and a relative humidity of 30% (flow rate 3 to 8 m / sec) for 5 minutes and then dried with dry air at 25 ° C and a relative humidity of 25% (flow rate 3 to 8 m / sec) for 20 minutes to arrive at an ink jet recording sheet of the invention carrying an ink receiving layer having a dry film thickness of 30 μm.

[Example 5]

Corresponding the following "silica dispersion B "composition was a slurry, containing ion-exchanged water, boric acid, dimethyldiallylammonium chloride polymer (Shallol DC902P, made by Dai-Ichi Kogyo Seiyaku), fine Silica particles and Zircosol ZA-30 manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd., dispersed in an Ultimizer, manufactured by Sugino Machine Ltd., once at 170 MPa to one Silicon dioxide dispersion B to arrive, the particles with a middle Diameter (mean particle diameter) of 120 nm.

Corresponding the following composition for the solution B for the Formation of the ink receiving layer was ion-exchanged water, SC-505, polyvinyl alcohol solution and Superflex 650-5 and with the silica dispersion B mixed to a solution B for the Formation of the ink receiving layer to get. It became an ink-jet recording sheet of Example 5 in similar A method as prepared in Example 1, except that the solution B for the Formation of the ink receiving layer was used.

"Silica B "

• (1) Fine silica particles of vapor phase method 15.0 parts (Aerosil 300SF75, Noppon Aerosil Co., Ltd.)
• (2) Ion-exchanged water 82, 32 parts
• (3) "Shallol DC-902P "(51.5% Solution) 1.31 parts (dispersant, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)
• (4) Zirconyl acetate "Zircosol ZA-30 (50% solution) "0.81 parts (prepared by Daiichi Kigenso Kagaku Kogyo Co., Ltd.)
• (5) boric acid 0.56 parts.

"Composition the solution B for the Formation of the ink receiving layer "

• (1) Silica dispersion B 59.5 parts
• (2) Ion-exchanged water 12.2 parts
• (3) Dimethylamine-epichlorohydrin-polyalkylene-polyamine polycondensate (50%) Solution) (SC-505, manufactured by Hymo Co., Ltd.) 0.1 parts
• (4) The following polyvinyl alcohol solution 26.0 parts
• (5) Cationically modified polyurethane 2.2 parts (Superflex 650-5 (25% solution)) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)

<composition the polyvinyl alcohol solution>

• (1) Polyvinyl alcohol 6.96 parts ("Denka POVAL H-24", manufactured by Denki Kagaku Kogyo K. K, saponification value: 95.6 mol%, degree of polymerization: 2400)
• (2) Polyoxyethylene lauryl ether 0.23 parts (Surface active Agent, Emulgen 109P, manufactured by Kao Corp.)
• (3) Diethylene glycol monobutyl ether 2.12 parts (butycenol 20P, manufactured by Kyowa Hakko Kogyo Co., Ltd.)
• (4) Ion exchange water 90.69 parts.

[Example 6]

A slurry containing ion exchanged water, 7.5% boric acid solution, dimethyldiallyl ammonium chloride polymer (Shallol DC902P, made by Dai-Ichi Kogyo Seiyaku), fine Silica particles and Zircosol ZA-30, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd., prepared according to the following composition for the "silica dispersion C ", was in one Ultimizer, manufactured by Sugino Machine Ltd. at 170 MPa to get to a silica dispersion C, the particles with a mean diameter (mean particle diameter) of 120 nm contained.

Subsequently were ion-exchanged water, 7.5% boric acid solution, SC-505, polyvinyl alcohol solution and Superflex 650-5 to the silica dispersion C with the following Composition for the solution C is added to form the ink receiving layer to form a solution C for formation to obtain the ink receiving layer.

"Silica C "

• (1) Fine silica particles of vapor phase method 15.0 parts (Aerosil 300SF75, manufactured by Nippon Aerosil Co., Ltd.)
• (2) Ion-exchanged water 78.5 parts
• (3) 7.5% boric acid solution (crosslinking agent) 4.4 parts
• (4) "Shallol DC902P "(51.5% solution) 1.31 Parts (dispersant, manufactured by Dai-Ichi Kogyo Seiyaku Co., Ltd.)
• (5) Zirconyl acetate "Zircosol ZA-30 "(50% solution)" 0.81 parts (prepared by Daiichi Kigenso Kagaku Kogyo Co., Ltd.)

"Composition the solution C for the Formation of the ink receiving layer "

• (1) Silica dispersion C 59.5 parts
• (2) Ion-exchanged water 12.2 parts
• (3) Dimethylamine-epichlorohydrin-polyalkylene-polyamine polycondensate (50%) Solution) (SC-505, manufactured by Hymo Co., Ltd.) 0.1 parts
• (4) The following polyvinyl alcohol solution 26.0 parts
• (5) Cationically modified polyurethane 2.2 parts (Superflex 650-5 (25% solution)) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)

<composition the polyvinyl alcohol solution>

• (1) Polyvinyl alcohol 6.96 parts (JM-33, manufactured from Japan VAM & POVAL Co., Ltd., saponification value 94.3 mol%, degree of polymerization: 3300),
• (2) Polyoxyethylene lauryl ether 0.23 parts (Surface active Agent, Emulgen 109P, manufactured by Kao Corp.)
• (3) Diethylene glycol monobutyl ether 2.12 parts (butycenol 20P, manufactured by Kyowa Hakko Kogyo Co., Ltd.)
• (4) Ion-exchanged water 90.69 parts.

(Preparation of Inkjet Recording Sheet)

The front surface of the support was corona discharge treated and the solution C for the formation of the ink receiving layer and the following solution PAC 1 were in-line mixed and coated thereon at coating amounts of 183 g / m ² and 11.4 g / m ² , respectively extrusion die. The support was then dried in a hot air dryer at 80 ° C (flow rate 3 to 8 m / sec) until the applied layer had a solids concentration of 20%. The applied layer showed a constant rate of drying during this period. The coated layer was dipped in a basic solution (pH 7.8) having the following composition for three seconds before showing a falling rate of drying, which allowed the deposition of the solution on the coated layer in an amount of 13 g / m ² . Then, it was dried at 65 ° C for 10 minutes (hardening step) to obtain an ink jet recording sheet of Example 6 which carried an ink receiving layer having a dry film thickness of 32 μm.

<Solution PAC 1>

• (1) Aqueous polyaluminum with a basicity of 83% (Alfine 83, manufactured by Taimei Chemicals Co., Ltd.) 20 parts
• (2) Ion-exchanged water 80 parts.

<composition the basic solution>

• (1) boric acid 0.65 parts
• (2) zirconium ammonium carbonate (28% aqueous solution) 0.33 parts Zircosol AC-7, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.)
• (3) Ammonium carbonate (reagent grade) 3.5 parts (manufactured by Kanto Kagaku Co. Inc.)
• (4) Ion-exchanged water 63.6 parts
• (5) Polyoxyethylene lauryl ether (2% aqueous solution) 30.3 parts (surface-active Agent, Emulgen 109P, manufactured by Kao Corp.)

Comparative Example 1

A slurry containing ion-exchanged water, dimethyldiallyl-ammonium chloride polymer (Shallol DC902P, manufactured by Dai-Ichi Kogyo Seiyaku), silica fine particles and Zircosol ZA-30 manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd. prepared according to the following composition for "silica dispersion solution C" was prepared in a sand mill ("Dyno-Mill type: KDL-PILT" manufactured by Shinmaru Enterprises Corp.) containing zirconia (ZrO ₂ ) spheres having a mean particle diameter of 0.65 mm, dispersed in an amount of 80% by volume to obtain a fine dispersion containing particles having an average diameter (mean particle diameter) of 140 nm.

Ion exchange Water, 7.5% boric acid solution, SC-505, polyvinyl alcohol and Superflex 650-5 became the silica dispersion in this order C according to the following Composition for the solution C for the Formation of the ink receiving layer was added, and the mixture was stirred to to a solution C for the Formation of the ink receiving layer to get.

"Silica C "

• (1) Fine silica particles of vapor phase method 15.0 parts (Aerosil 300SF75, manufactured by Nippon Aerosil Co., Ltd.)
• (2) Ion-exchanged water 82.9 parts
• (4) "Shallol DC902P" (51.5% solution) 1.31 parts (dispersant, manufactured by Dai-Ichi Kogyo Seiyaku Co., Ltd.)
• (5) Zirconyl acetate "Zircosol ZA-30 "(50% solution)" 0.81 parts (prepared Daiichi Kigenso Kagaku Kogyo Co., Ltd.).

"Composition the solution C for the Formation of the ink receiving layer "

• (1) Silica dispersion C 59.5 parts
• (2) Ion-exchanged water 7.8 parts
• (3) 7.5% boric acid solution (crosslinking agent) 4.4 parts
• (4) Dimethylamine-epichlorohydrin-polyalkylene-polyamine polycondensate (50%) Solution) (SC-505, manufactured by Hymo Co., Ltd.) 0.2 parts
• (5) The following polyvinyl alcohol solution 26.0 parts (6) Cationic modified polyurethane 2.2 parts (Superflex 650-5 (25% solution)) prepared Dai-ichi Kogyo Seiyaku Co., Ltd.)

<composition the polyvinyl alcohol solution>

• (1) Polyvinyl alcohol 6.96 parts PVA-224, prepared from Kuraray, saponification value: 88.0 mol%, degree of polymerization: 2400)
• (2) Polyoxyethylene lauryl ether 0.23 parts (Surface active Agent, Emulgen 109P, manufactured by Kao Corp.)
• (3) Diethylene glycol monobutyl ether 2.12 parts (butycenol 20P, manufactured by Kyowa Hakko Kogyo Co., Ltd.)
• (4) Ion exchange water 90.69 parts.

(Preparation of Inkjet Recording Sheet)

The front side of the support was treated by corona discharge as in Example 1, and the solution C for the formation of the ink receiving layer and the solution PAC 1 were in-line mixed and coated thereon at coating rates of 183 g / m ² and 11.4 g / m, respectively. m ² using an extrusion die coater. The support was then dried in a hot air dryer at 80 ° C (flow rate 3 to 8 m / sec) until the applied layer had a solids concentration of 20%. The applied layer showed a constant rate of drying during this period. The coated layer was dipped in a basic solution (pH 7.8) having the following composition for three seconds before showing a falling rate of drying, which allowed the deposition of the solution on the coated layer in an amount of 13 g / m ² . Then, it was dried at 65 ° C for 10 minutes (hardening step) to arrive at an ink jet recording sheet of Comparative Example 1 carrying an ink receiving layer having a dry film thickness of 32 μm.

Comparative Example 2

One Ink jet recording sheet of Comparative Example 2 was in a similar way Manner as prepared in Comparative Example 1, with the exception of that in the solution C used to form the ink receiving layer polyvinyl alcohol replaced by "PVA235, made by Kuraray "with one Saponification value of 88.0 mol% and a degree of polymerization of 3500th

Comparative Example 3

One Ink jet recording sheet of Comparative Example 3 was in a similar way Manner as prepared in Comparative Example 1, with the exception of that in the solution C used to form the ink receiving layer polyvinyl alcohol was replaced by "JC-25" manufactured by Japan VAM & POVAL Co., Ltd. with a saponification value of 99.1 mol% and a degree of polymerization from 2400.

The The sheet obtained in Comparative Example 3 had a lower ink absorption efficiency and gave No inkjet recording sheet to be evaluated, as described below.

Comparative Example 4

One Ink jet recording sheet of Comparative Example 4 was in a similar way Manner as prepared in Example 1, except that Zirkosol ZA-30 was not added as Zirkonylacetat.

Comparative Example 5

One Ink jet recording sheet of Comparative Example 5 was in a similar way Manner as prepared in Example 1, except that the solution PAC 1 was not mixed in-line.

Comparative Example 6

One Ink jet recording sheet of Comparative Example 6 was in a similar way A method as prepared in Example 1, except that the cationically modified polyurethane (Superflex 650-5 (25% solution)) not was added.

The solutions obtained in this way for forming the ink receiving layer and ink jet recording media examined in the following tests. The results are in table 1 compiled.

"Viscosity measurement"

The viscosity of the solution for the formation of the ink receiving layer was determined by using a Rheo Stress 600 manufactured by Haake at a test temperature of 30 ° C and a shear rate of 10 ^-2 sec ^-1 .

"Print Density"

It was for Each inkjet recording sheet printed with a black image Ink in an inkjet printer "PM-G800", manufactured by Seiko Epson Corporation and an inkjet printer "Pixus iP8600" manufactured by Canon Inc. The optical density of the printed sample was below Use of X-Lite.

"Tint of the Halftone gray area "

A gray color was created using Adobe Photoshop under Use of blue, greener and red color with qualities (grades) of 128. The gray image was for each ink jet recording paper in an inkjet printer "PM-G800" manufactured by Seiko Epson Corporation and an inkjet printer "Pixus iP8600, manufactured by Canon Inc.

To the samples were subjected to pressure under the conditions of 23 ° C and 60% relative humidity for Dried for 24 hours, and D50 and the tint at a viewing angle of 2 degrees (L, a * value and b * value) were measured using a "spectrophotometer CM-7300d " determined by Konica Minolta. The a * value and b * value closer to 0 shows a color closer to neutral gray and is therefore advantageous.

"Ink absorption effectiveness"

It was a black colored Image on a paper under conditions of 30 ° C and 80% relative humidity using an inkjet printer "PM-G800" manufactured by Seiko Epson Corporation, educated. An ordinary one Paper was printed immediately after printing on the printed paper arranged and gently pressed, and the degree of the ordinary Paper transferred Ink was analyzed by visual inspection and accordingly assessed the following criteria:

• A: no transmission
• B: something transfer
• C: significant transmission.

"Stability of the viscosity of the Ink-receiving layer-forming solution "

It became the viscosity change the solution forming the ink-receiving layer during storage at 30 ° C for 4 days rated.

• A: less than twice higher than the viscosity immediately after production
• B: 2.1 to 5 times higher as the viscosity immediately after production
• C: 5.1 times or more higher as the viscosity immediately after production.

As Table 1 illustrates the present invention An ink jet recording medium prepared from a coating solution containing in terms of viscosity stabilized, allowing high density printing, wherein a favorable printed gray image is available and that is an advantageous Ink absorption efficiency Has.

Claims (12)

An ink jet recording medium comprising a carrier and an ink receiving layer formed thereon, the inorganic ones fine particles, a water-soluble Aluminum compound, a zirconium compound, a cationic modified self-emulsifying polymer, a polyvinyl alcohol with a saponification value of 92 to 98 mol% and a crosslinking agent contains. An ink jet recording medium according to claim 1, wherein the inorganic fine particles are fine silica particles are. An ink-jet recording medium according to claim 2, wherein said fine silica particles are vapor phase method silica particles having a BET specific surface area of 200 m ² / g or more. An ink jet recording medium according to claim 1, wherein the degree of polymerization of the polyvinyl alcohol 1,500 to Is 3,600. An ink jet recording medium according to claim 1, wherein the water-soluble Aluminum compound, a basic polyaluminum hydroxide compound is. An ink jet recording medium according to claim 1, wherein the zirconium compound is zirconyl acetate. An ink jet recording medium according to claim 1, wherein the self-emulsifying polymer is a cationic group containing urethane resin. An ink jet recording medium according to claim 1, wherein the crosslinking agent is boric acid or a borate salt. A method of manufacturing an ink jet recording medium full: Make a dispersion by colliding inorganic fine particles and a zirconium compound or carry out inorganic fine particles and a zirconium compound an opening using a high pressure disperser; Produce an ink receiving layer-forming solution by adding a cationic modified self-emulsifying polymer, a polyvinyl alcohol having a saponification value of 92 to 98 mol% and a crosslinking agent to the dispersion; and Forming a coated layer Applying a coating solution, by in-line mixing of a water-soluble aluminum compound into the ink receiving layer forming solution a carrier. A method of manufacturing an ink jet recording medium according to claim 9, further comprising crosslinking and curing the coated layer by applying a basic solution with a pH of 7.1 or more either (1) simultaneously with the application of the coating solution or (2) before the coated layer has a falling rate of drying while drying the coated layer. A method of manufacturing an ink jet recording medium full: Make a dispersion by colliding inorganic fine particles, a zirconium compound and a Crosslinking agent or by guiding inorganic fine particle, a zirconium compound of a crosslinking agent through an opening using a high pressure disperser; Produce an ink receiving layer-forming solution by adding a cationic modified self-emulsifying polymer and a polyvinyl alcohol having a saponification value of 92 to 98 mol% to the dispersion; and Forming a coated layer by applying a Coating solution by in-line mixing of a water-soluble aluminum compound into the ink receiving layer forming solution a carrier. A method of manufacturing an ink jet recording medium according to claim 11, further comprising crosslinking and curing the coated layer by applying a basic solution with a pH of 7.1 or more either (1) simultaneously with the application of the coating solution or (2) before the coated layer has a falling rate of drying while drying the coated layer.